• <noscript id="y4y0w"><source id="y4y0w"></source></noscript>
    <table id="y4y0w"><option id="y4y0w"></option></table>
  • <li id="y4y0w"></li>
    <noscript id="y4y0w"></noscript>
    <noscript id="y4y0w"><kbd id="y4y0w"></kbd></noscript>
    <noscript id="y4y0w"><source id="y4y0w"></source></noscript>
    <menu id="y4y0w"></menu>
    <table id="y4y0w"><rt id="y4y0w"></rt></table>
  • COG噴吹量對高爐冶煉過程影響數值模擬

    Numerical simulation of the effect of coke oven gas blowing rate on the blast furnace smelting process

    • 摘要: 基于國家“碳減排、碳中和”戰略,向高爐中噴吹富氫氣體成為有效減排的重要方法,其中關于高爐噴吹焦爐煤氣(COG)的研究也得到了廣泛關注,但針對COG噴吹量對高爐冶煉過程影響的相關研究相對較少. 在此基礎上,本文采用計算流體動力學數值模擬方法,探究COG噴吹量對高爐內煤粉燃燒率、氣體還原反應、風口處焦炭反應及軟熔帶等因素的影響. 結果表明,隨著COG噴吹量由30 m3?min–1提升至120 m3?min–1,H2O、CO、CO2、H2等組分的含量表現出一定程度的上升趨勢. 從煤粉燃燒率的角度看,隨著COG噴吹量的增加,煤粉的揮發反應基本相同,而水煤氣反應得到增強. 同時以氫氣為主的還原路徑以及水煤氣反應得到強化,且爐內的軟熔帶位置以及形狀發生改變,基于本次模擬,COG噴吹量達到120 m3?min–1時相對適宜,其軟熔帶的厚度有所減小,透氣性得到改善,氣速分布相對均勻.

       

      Abstract: Blowing hydrogen-rich gas into the blast furnace has become an important method for reducing emissions, aligning with the national strategy for carbon emissions reduction and carbon neutrality. Research on blowing coke oven gas (COG) into the blast furnace has also received widespread attention; however only little research has been conducted on the effect of the blowing amount on blast furnace smelting. This study adopts the computational fluid dynamics (CFD) method to explore the effect of COG blowing amount on the pulverized coal combustion rate, gas reduction reactions, and coke reactions at the tuyere and cohesive zone of the blast furnace. The results show a decreasing trend in gas temperature at the tuyere due to the injection of coal powder. Afterward, the gas temperature increaseed significantly, reaching its peak as it exits the raceway. This is mainly attributed to the intense combustion of coal powder and gas-phase combustible components. The temperature then gradually decreased as the gas moved away from the raceway. As the COG injection rate increased from 30 to 120 m3?min–1, the contents of H2O, CO, CO2, and H2 showed a certain degree of upward trend. From the perspective of the coal powder combustion rate, the increased COG injection sustained the volatilization reaction of coal powder and enhanced the water-gas reaction. With the increase in COG injection volume, the reducing atmosphere in the furnace was enhanced. Owing to the competitive effect between H2 and CO, the CO reduction pathway decreased, while the H2 reduction pathway increased. The reaction intensity of coke in the furnace body also changes with the increasing COG injection. As the COG injection increased, the H2 content in the furnace belly gas continued to rise, the water-gas reaction was enhanced, and the combustion reaction of coke was reduced. During the increase of the COG injection rate from 30 to 90 m3?min–1, the thickness of the cohesive zone continued to increase, resulting in decreased permeability and an elevation of the high-pressure zone, which forced more gas to flow rapidly toward the center. However, when the injection rate reached 120 m3?min–1, the thickness of the cohesive zone decreased, permeability improved, the high-pressure zone shifted downward, and the gas velocity distribution at the center became relatively uniform. After injecting COG, the temperature inside the furnace decreased, with significant changes observed in the waist and lower regions, and the high-temperature zone shrank. This occurred because the injected COG gas, at normal temperature, introduced low-temperature gas into the furnace, and the gasification of hydrocarbons absorbed heat. This process increased the total amount of combustion products, thereby requiring more heat for heating. However, as the COG injection volume and oxygen enrichment rate increased, the high-temperature area gradually expanded.

       

    /

    返回文章
    返回
  • <noscript id="y4y0w"><source id="y4y0w"></source></noscript>
    <table id="y4y0w"><option id="y4y0w"></option></table>
  • <li id="y4y0w"></li>
    <noscript id="y4y0w"></noscript>
    <noscript id="y4y0w"><kbd id="y4y0w"></kbd></noscript>
    <noscript id="y4y0w"><source id="y4y0w"></source></noscript>
    <menu id="y4y0w"></menu>
    <table id="y4y0w"><rt id="y4y0w"></rt></table>
  • 啪啪啪视频